23421456721009 has 2 divisors, whose sum is σ = 23421456721010. Its totient is φ = 23421456721008.

The previous prime is 23421456720971. The next prime is 23421456721021. The reversal of 23421456721009 is 90012765412432.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15883532722225 + 7537923998784 = 3985415^2 + 2745528^2 .

It is a cyclic number.

It is not a de Polignac number, because 23421456721009 - 2⁴³ = 14625363698801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 23421456721009.

It is not a weakly prime, because it can be changed into another prime (23421456721079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11710728360504 + 11710728360505.

It is an arithmetic number, because the mean of its divisors is an integer number (11710728360505).

Almost surely, 2^{23421456721009} is an apocalyptic number.

It is an amenable number.

23421456721009 is a deficient number, since it is larger than the sum of its proper divisors (1).

23421456721009 is an equidigital number, since it uses as much as digits as its factorization.

23421456721009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 46.

The spelling of 23421456721009 in words is "twenty-three trillion, four hundred twenty-one billion, four hundred fifty-six million, seven hundred twenty-one thousand, nine".